Control-k - Remove text from the cursor to the end of the line,
or remove the line if it is empty

Del / Control-d - delete the current character

Backspace - delete the previous character

Edit widgets may be configured with a line limit which limits the
number of lines of text the widget will store. It does not provide
any limit control on the length of its lines, though.

Edit widgets support multi-column characters. (For some
information, see http://www.unicode.org/reports/tr11/.) When the
edit widget scrolling reaches a point where a wide character cannot
be drawn because it is bisected by the editing window's boundary,
it will be replaced with an indicator ("$") until the scrolling
window is moved enough to reveal the character. This is done to
preserve the relative alignment of all of the rows in the widget in
the presence of characters of different widths. Note that this is
a visual aid only and does not affect the underlying text content
of the widget.

Set the contents of the edit widget. Newlines will be used to
break up the text in multiline widgets. If the edit widget has a
line limit, only those lines within the limit will be set. If the edit
widget has a line length limit, lines will be truncated.

Apply an editing transformation to the edit widget's text. If the
transformation modifies the text or the cursor, the appropriate
event handlers will be notified. If a line limit is in effect and
the transformation violates it, the transformation will be ignored.

Register handlers to be invoked when the edit widget has been
''activated'' (when the user presses Enter while the widget is
focused). These handlers will only be invoked when a single-line
edit widget is activated; multi-line widgets never generate these
events.